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Background: Single-center trials demonstrated moderate-substantial level of interobserver agreement in the evaluation of ultrasound (US) features of thyroid nodules. Multicenter studies on US agreement, however, are scanty, and data on intraobserver agreement are poor. Aim of the study was to assess inter- and intraobserver agreement between different thyroid centers and different specialists. Methods: A blinded analysis of 100 electronically recorded thyroid nodule US images was conducted in three large-volume thyroid centers by seven radiologists and endocrinologists. The evaluation was repeated after randomization 4 months later. The following US characteristics were evaluated: composition, echogenicity, margins, intranodular echogenic spots, vascularity, and shape. Thyroid nodules were also classified according to AACE/ACE/AME, EU-TIRADS, ATA, and ACR-TIRADS US classifications. Intra- and interobserver agreement was calculated using cross-tabulation expressed as mean Cohen's Kappa. Results: Interobserver agreement for US features: K-coefficient was 0.53 for composition, 0.47 for echogenicity, 0.46 for intranodular vascularity, and 0.33 for margins of the nodules. For echogenic foci, the K-coefficient was 0.47 for microcalcifications, 0.38 for macrocalcifications, 0.11 for the subcategory comet-tail artifacts, and 0.42 for shape. Operators resulted uncertain on hyperechoic foci definition in 16% of cases and described them as "hyperechoic foci of uncertain significance." Interobserver Cohen-K for US classification systems was 0.44 for AACE, 0.42 for ACR-TIRADS, 0.39 EU-TIRADS, and 0.34 for ATA. Intraobserver agreement: the K-coefficient for nodule US features was 0.62 for intranodular vascularity, 0.58 for composition, 0.60 for echogenicity, 0.54 for macrocalcifications, 0.55 for microcalcifications, 0.47 for comet tails, 0.39 for margins, and 0.35 for shape. Intraobserver Cohen-K for US classification systems was 0.54 for AACE, 0.49 for ACR-TIRADS, 0.38 for ATA, and 0.33 for EU-TIRADS. Conclusions: Intraobserver reproducibility for thyroid nodule US reporting and US classification systems appears fairly adequate, while the interobserver agreement between different centers is lower than that assessed in single-center trials. Reporting and rating ability of thyroid US examiners still appear not consistent. An unified lexicon of thyroid US features, a simplified method of classification, and a dedicated training in the description of thyroid US findings may increase the observers' agreement and the predictive value of US classification systems in real world practice. [ABSTRACT FROM AUTHOR]

Background: The current approach for calculating the starting dose of levothyroxine (LT4) after total thyroidectomy is based on the patient's body weight (BW). The aim of the study was to identify the major predictive factors of LT4 requirement and to elaborate a new method to improve the accuracy of the LT4 starting dose after total thyroidectomy. Methods: The study consists of two parts. The first part consisted of the retrospective identification of 92 adult patients (retrospective cohort) who had undergone a total thyroidectomy for benign disease and who had begun LT4 treatment at a dose of 1.6 μg/kg/day. Adjustments to optimize the LT4 dose were then performed at the post-surgery follow-up on the basis of serum thyrotropin (TSH) levels. The results of this retrospective analysis were used to formulate a nomogram for a proper calculation of the LT4 starting dose that was then used prospectively in the second part of the study on 31 consecutive patients (prospective cohort). Results: At the first follow-up, 37 (40%) patients from the retrospective cohort were euthyroid. Univariate analysis indicated significant correlations between the optimal dose of LT4 and BW, body mass index (BMI), age, preoperative mean corpuscular volume, and free triiodothyronine (fT3). The optimal dose of LT4, analyzed for BMI and age, showed an inverse relationship with these two parameters, and ranged from 1.4 to 1.8 μg/kg/day. In the prospective cohort, the use of an age- and BMI-related nomogram improved the prediction of the optimal LT4 starting dose, with 68% of patients being euthyroid at the first follow-up compared to 41% of patients reported to have reached euthyroid state using the best strategy proposed in the literature. Conclusions: This study confirms that BW is not the only variable for predicting LT4 requirement, as it decreases with the increase in age and BMI, probably due to the relative decrease of lean body mass. A new correlation between optimal dose and presurgical levels of fT3 and mean corpuscular volume was observed. We propose an easy and more efficient method of calculating LT4 starting dose after total thyroidectomy for benign disease. [ABSTRACT FROM AUTHOR]